Energie aus dem Grünland - eine nachhaltige Entwicklung?

In many regions of Baden-Wurttemberg permanent grassland is shaping the landscape and fulfils important functions in the protection of nature, soil, and water. However, traditional ways of using grassland for forage production are vanishing as a result of progress in breeding, the technological advance in milk production technology as well as structural adaptations in agriculture. According to calculations, about 167,000 ha - over one quarter of the total grassland in Baden-Wurttemberg - will no longer be used for animal husbandry until 2015. Almost 90% of this surplus area could be applied for the production of energy. In this study, the applicability and economic efficiency of different techniques for energy production from intensively or non-intensively used grassland as well as from grassland converted into maize fields or short-rotation poplars shall be analysed. On the basis of the integrative sustainability concept and 18 sustainability indicators selected, a holistic evaluation of the different technologies will be made. The material and energy flows will be balanced by means of a life cycle analysis program. In general, the different utilisation paths have both positive and negative impacts on aspects of sustainability. Positive effects of the use of grass for energy production are the preservation of biodiversity, the protection of soil, water, and the cultural landscape as well as the savings of non-renewable energy and the reduction of greenhouse gas emissions. However, the emissions increasing health risks, acidification, and eutrophication are counting negative. Even when agricultural policy premiums paid are taken into account, the production of biogas from grass silage in larger plants (> 500 kW el ) is economically efficient. By using the heat available from electricity production from biogas, profitability could be further improved. Profits might also be achieved with the combustion of hay in small combustion units. Despite the relatively high energy prices and the strong financial support of electricity production from biomass, however, effects on employment and income in agriculture will be modest.